Merge branch 'for-next/mm' into for-next/core

* for-next/mm: (24 commits)
  Revert "arm64: mm: Unmap kernel data/bss entirely from the linear map"
  Revert "arm64: mm: Defer remap of linear alias of data/bss"
  arm64/mm: Rename ptdesc_t
  arm64: mm: Defer remap of linear alias of data/bss
  KVM: arm64: Omit tag sync on stage-2 mappings of the zero page
  arm64: Avoid double evaluation of __ptep_get()
  kasan: Move generic KASAN page tables out of BSS too
  arm64: Rename page table BSS section to .bss..pgtbl
  arm64: mm: Unmap kernel data/bss entirely from the linear map
  arm64: mm: Map the kernel data/bss read-only in the linear map
  mm: Make empty_zero_page[] const
  sh: Drop cache flush of the zero page at boot
  powerpc/code-patching: Avoid r/w mapping of the zero page
  arm64: mm: Don't abuse memblock NOMAP to check for overlaps
  arm64: Move fixmap and kasan page tables to end of kernel image
  arm64: mm: Permit contiguous attribute for preliminary mappings
  arm64: kfence: Avoid NOMAP tricks when mapping the early pool
  arm64: mm: Permit contiguous descriptors to be manipulated
  arm64: mm: Preserve non-contiguous descriptors when mapping DRAM
  arm64: mm: Preserve existing table mappings when mapping DRAM
  ...

5 files changed, 13 insertions, 7 deletions

diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
index a81cb4aa4738..30cd7f804398 100644
--- a/arch/arm64/kernel/efi.c
+++ b/arch/arm64/kernel/efi.c
@@ -31,7 +31,7 @@ static bool region_is_misaligned(const efi_memory_desc_t *md)
  * executable, everything else can be mapped with the XN bits
  * set. Also take the new (optional) RO/XP bits into account.
  */
-static __init ptdesc_t create_mapping_protection(efi_memory_desc_t *md)
+static __init ptval_t create_mapping_protection(efi_memory_desc_t *md)
 {
 	u64 attr = md->attribute;
 	u32 type = md->type;
@@ -85,7 +85,7 @@ static __init ptdesc_t create_mapping_protection(efi_memory_desc_t *md)
 
 int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
 {
-	ptdesc_t prot_val = create_mapping_protection(md);
+	ptval_t prot_val = create_mapping_protection(md);
 	bool page_mappings_only = (md->type == EFI_RUNTIME_SERVICES_CODE ||
 				   md->type == EFI_RUNTIME_SERVICES_DATA);
 
diff --git a/arch/arm64/kernel/pi/map_kernel.c b/arch/arm64/kernel/pi/map_kernel.c
index a852264958c3..fb44cbdd2f29 100644
--- a/arch/arm64/kernel/pi/map_kernel.c
+++ b/arch/arm64/kernel/pi/map_kernel.c
@@ -165,7 +165,7 @@ static void noinline __section(".idmap.text") set_ttbr0_for_lpa2(phys_addr_t ttb
 static void __init remap_idmap_for_lpa2(void)
 {
 	/* clear the bits that change meaning once LPA2 is turned on */
-	ptdesc_t mask = PTE_SHARED;
+	ptval_t mask = PTE_SHARED;
 
 	/*
 	 * We have to clear bits [9:8] in all block or page descriptors in the
diff --git a/arch/arm64/kernel/pi/map_range.c b/arch/arm64/kernel/pi/map_range.c
index de52cd85c691..761b14893f74 100644
--- a/arch/arm64/kernel/pi/map_range.c
+++ b/arch/arm64/kernel/pi/map_range.c
@@ -31,7 +31,7 @@ void __init map_range(phys_addr_t *pte, u64 start, u64 end, phys_addr_t pa,
 		      u64 va_offset)
 {
 	u64 cmask = (level == 3) ? CONT_PTE_SIZE - 1 : U64_MAX;
-	ptdesc_t protval = pgprot_val(prot) & ~PTE_TYPE_MASK;
+	ptval_t protval = pgprot_val(prot) & ~PTE_TYPE_MASK;
 	int lshift = (3 - level) * PTDESC_TABLE_SHIFT;
 	u64 lmask = (PAGE_SIZE << lshift) - 1;
 
@@ -88,7 +88,7 @@ void __init map_range(phys_addr_t *pte, u64 start, u64 end, phys_addr_t pa,
 	}
 }
 
-asmlinkage phys_addr_t __init create_init_idmap(pgd_t *pg_dir, ptdesc_t clrmask)
+asmlinkage phys_addr_t __init create_init_idmap(pgd_t *pg_dir, ptval_t clrmask)
 {
 	phys_addr_t ptep = (phys_addr_t)pg_dir + PAGE_SIZE; /* MMU is off */
 	pgprot_t text_prot = PAGE_KERNEL_ROX;
diff --git a/arch/arm64/kernel/pi/pi.h b/arch/arm64/kernel/pi/pi.h
index aec3172d4003..5dfd8484d200 100644
--- a/arch/arm64/kernel/pi/pi.h
+++ b/arch/arm64/kernel/pi/pi.h
@@ -35,4 +35,4 @@ void map_range(phys_addr_t *pte, u64 start, u64 end, phys_addr_t pa,
 
 asmlinkage void early_map_kernel(u64 boot_status, phys_addr_t fdt);
 
-asmlinkage phys_addr_t create_init_idmap(pgd_t *pgd, ptdesc_t clrmask);
+asmlinkage phys_addr_t create_init_idmap(pgd_t *pgd, ptval_t clrmask);
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index e1ac876200a3..d3ed59abab38 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -349,9 +349,15 @@ SECTIONS
 	_edata = .;
 
 	/* start of zero-init region */
-	BSS_SECTION(SBSS_ALIGN, 0, 0)
+	BSS_SECTION(SBSS_ALIGN, 0, PAGE_SIZE)
 	__pi___bss_start = __bss_start;
 
+	/* page table BSS starts here - preceding data/BSS is omitted from the linear map */
+	.pgtbl : ALIGN(PAGE_SIZE) {
+		*(.bss..pgtbl)
+	}
+	ASSERT(ADDR(.pgtbl) == __bss_stop, ".pgtbl must follow BSS")
+
 	. = ALIGN(PAGE_SIZE);
 	__pi_init_pg_dir = .;
 	. += INIT_DIR_SIZE;